Frac manifolds, also referred to herein as zipper manifolds, are designed to allow hydraulic fracturing operations on multiple wells using a single frac pump output source. Frac manifolds are positioned between the frac pump output and frac trees of individual wells. A frac manifold system receives fracturing fluid from the pump output and directs it to one of many frac trees. Fracturing fluid flow is traditionally controlled by operating valves to isolate output to a single tree for fracking operations.
Frac zipper manifolds may be rigged up to frac trees before frac equipment arrives at the well site. Once onsite, the frac equipment need only be connected to the input of the frac manifold. Because individual frac trees do not need to be rigged up and down for each fracking stage and because the same frac equipment can be used for fracking operations on multiple wells, zipper manifolds reduce downtime for fracking operations while also increasing safety and productivity. Another benefit includes reducing equipment clutter at a well site.
Despite their benefits, further efficiencies and cost savings for zipper manifolds may be gained through improved designs. In particular, typically treatment fluid in the zipper manifold passes to frac trees via goat heads or frac heads and frac iron, but there are several drawbacks to using such setups to span the distance between the zipper manifold and each frac tree. Goat heads, or frac heads, traditionally employ multiple downlines and restraints that clutter the area between the zipper manifold and the frac tree, which can make for a more difficult and less safe work environment to operate and maintain the frac equipment.
Some designs have been developed to avoid using frac iron. One design uses a single line made from studded elbow blocks and flow spools with swiveling flanges. Such a design is disclosed in, for example, U.S. Pat. Nos. 9,932,800, 9,518,430, and 9,068,450. A similar design is currently offered for sale by Cameron International of Houston, Tex., under the brand name Monoline. One drawback of this design is that the weight of the equipment combined with the potentially awkward orientation of the lines can make installation difficult and can place uneven or increased stress on the connections to the frac manifold and/or the frac tree. Another drawback is that using a single line to connect the frac manifold to the frac tree can lead to increased velocity and turbulence of the flow, when compared to using multiple lines. Such conditions may lead to a greater risk of erosion in the frac tree. Replacing a damaged frac tree can be very expensive and time-consuming. Accordingly, what is needed is an apparatus, system, or method that addresses one or more of the foregoing issues related to frac zipper manifolds, among one or more other issues.